1. Field of the Invention
The present invention relates to a constant pressure pressurizing water pump. More particularly, the present invention relates to a water pump for providing users with a stable pressure water source after pressurizing tap water. More specifically, the present invention relates to a water pump that can be used indoors for water supply.
2. Description of the Related Art
It is well known to use a first pressurizing water pump for pumping tap water into a storage tank on top of a building for the purposes of compensating insufficient pressure of tap water and to use a second pressurizing water pump for pumping water in the storage tank to the users in the building. The second pressurizing water pump is mounted between the storage tank and the piping at the users end. Tap water in the storage tank is pressurized before fed to the users. When a faucet is opened by a user, the pump is activated if a pressure detection switch detects that the water pressure in the piping drops below a predetermined value. When the faucet is closed, the pump keeps on running until the water pressure in the piping reaches a predetermined higher pressure, and the pressure detection switch sends a signal to turn off the pump.
Such a pressurizing water pump is used indoors, and the pump is repeatedly turned on and off due to various amounts of water output via the faucet, resulting in unstable output of water, which causes problems to a user taking a hot water bath. The temperature and pressure of the output water are unstable. Ignition of the water heater is also unstable.
Taiwan Patent Publication No. 500187 to Applicant discloses a pressurizing water pump including a pump and a pressure tank for providing a stable pressure water source. The pressure tank includes a flexible membrane in a housing to separate an interior of the pressure tank into two independent chambers one of which is filled with air. A check valve is mounted between the pressure tank and the pump. When the pressure in the pressure tank reaches a predetermined higher value, the pump is turned off. When the pressure in the pressure tank drops to a predetermined value, the pump is activated. When a faucet at a user end is opened, the pressure in the pressure tank is kept at a low value such that the pressurizing water pump can supply stable pressure tap water to the user to provide stable water output and to allow smooth ignition of the water heater.
The check valve is mounted in a chamber in the pressure tank and coupled with an upper cover of the pump, and the pressure tank is mounted on a flange of the storage tank and has an upper cover fixed to the flange. Furthermore, additional couplers are required for mounting the pressurizing water pump to the piping. All of these render a bulky structure and requires troublesome, inconvenient assembly and maintenance. Specifically, the whole pressurizing water pump must be detached if maintenance of the pressure tank is required.
It is therefore a need in a pressurizing water pump that allows easy assembly and maintenance while supplying constant pressure tap water to users.